<div>
  <table>
    <tr>
      <?php foreach (Tools::$letters as $i => $letter): ?>
        <?php if ($i%4==0): ?>
        </tr>
        <tr>
        <?php endif ?>
        <td>
          <a style="text-decoration: underline" href="<?php echo url_for('@author_by_letter?letter='.$letter) ?>">
            <?php echo ucwords($letter) ?>
          </a>
          <br />
          <?php foreach($authors[$letter] as $j => $author): ?>
            <a href="<?php echo url_for('author_show', $author) ?>">
              <?php echo $author->getName() ?>
            </a>
            <br />
          <?php endforeach ?>
          <br />
        </td>
      <?php endforeach ?>
    </tr>
  </table>
</div>
